The present invention relates to: a board supporting mechanism; a board supporting method; a component mounting apparatus utilizing the board supporting mechanism, and a component mounting method utilizing the board supporting method to mount a component on a circuit board; a viscous material applying apparatus and a viscous material applying method for applying a viscous material such as cream solder, adhesive, or silver paste onto a circuit board; a support pin; and a pin-erecting guide plate. More specifically, the present invention relates to: a board supporting mechanism and a board supporting method capable of supporting a circuit board from a bottom side thereof upon mounting a component or upon applying a viscous material; a component mounting apparatus and a viscous material applying apparatus respectively utilizing the board supporting mechanism and a component mounting method and a viscous material applying method respectively utilizing the board supporting method; a support pin; and a pin-erecting guide plate.
FIG. 11 illustrates one example of a component mounting apparatus. As illustrated in FIG. 11, the component mounting apparatus 101 includes a component supplying section 102 for supplying components to be mounted, a mounting head 104 for taking out the component from the component supplying section 102 by utilizing a suction nozzle 103 and mounting the component on a circuit board 114, a transfer robot 105 for transferring the mounting head 104 to a predetermined position, a component recognizing device 106 for picking up an image of the component held by the suction nozzle 103 to recognize a position and an angular deviation thereof, a board holding device 107 for carrying in and holding the circuit board 114, and a control section 109 for controlling general operations.
When the component mounting apparatus 101 configured as described above is actuated, the mounting head 104, transferred by the transfer robot 105, is moved to a position facing a component supplying device 108 provided on the component supplying section 102, and allowed to take a component out of the component supplying device 108 by utilizing the suction nozzle 103. Then, the suction nozzle 103 is moved to a position facing the component recognizing device 106 by the movement of the mounting head 104, so that the holding state of the component including the position and the angular deviation of the component that has been suction-held is recognized.
In these operations, a circuit board 114 is carried in the component mounting apparatus 101, and position-held at a predetermined mountable position by the board holding device 107. The mounting head 104 with the component being held by the suction nozzle 103 is transferred by the transfer robot 105 and moved to a position facing a top face of the circuit board 114. A board recognizing device 115 attached to the mounting head 104 picks up an image of the circuit board 114 to recognize a position and an angular deviation thereof, and transmits the results of recognition to the control section 109. The control section 109 has preliminarily read NC data in which component mounting positions of respective components to be mounted onto the circuit board 114 have been recorded. Based on the state of the component inputted from the component recognizing device 106 and the state of the circuit board 114 inputted from the board recognizing device 115, the control section 109 instructs to carry out necessary corrections with respect to the position and the angle of the suction nozzle 103.
Based on the instructions, the mounting head 104 corrects the position and the angle of the component 110, and mounts the component 110 on the component mounting position on the circuit board 114 by utilizing the suction nozzle 103. After the component 110 mounting, the mounting head 104, again transferred by the transfer robot 105, is moved to the position facing the component supplying device 108, and thereafter, the aforementioned operations are repeated. After having finished mounting all the predetermined components, the circuit board 114 is carried out of the component mounting apparatus 101 by the board holding device 107, and the next circuit board 114 is carried in, so that the aforementioned operations are repeated.
FIG. 12 illustrates the board holding device 107 for holding the circuit board 114 at the mountable position, and herein, one portion on the front side is exploded. In FIG. 12, the circuit board 114 is held by a pair of rail units 121 that are extended in an X1 direction and made face to face with each other. Grooves 122 are formed in the respective rail units 121 so as to be made face to face with each other, and flat belts 123 are extended to pass along the grooves 122 so as to move therein. In FIG. 12, the flat belt 123 is illustrated as two portions, which are connected to each other at two ends in the X1 direction, not illustrated, to form an endless belt, and engaged with a driving source such as a motor. The circuit board 114, the two ends of which are fitted to the paired grooves 122 facing each other, is placed on the paired flat belts 123, and can be moved and transferred in the X1 direction in FIG. 11.
One of the rail units 121 (for example, one on the right side of FIG. 12) is allowed to move in the direction opposing to the other rail unit 121 (the other one being on the left side) (in a Y1 direction), and by this movement of the one rail unit 121, it becomes possible to transfer and hold circuit boards 114 having various width dimensions. A reference rail 124 having an L-shaped cross section is secured to a main rail 125 on the top face of each of the rail units 121 by securing pins 126. The face (bottom face) of the L-shaped reference rail 124 on the side opposing to the circuit board 114 restricts the upward movement of the circuit board 114, and forms an upward reference face in a Z1 direction with respect to the circuit board 114 at the time of mounting a component.
A support table 127 is positioned below the two rail units 121, and a pin supporting plate 130, made of metal and placed on the support table 127, holds a plurality of support pins 128 each made of metal in the Z1 direction of FIG. 12. As will be described later, the support pins 128 are brought into contact with the bottom face of the circuit board 114 so as to support the circuit board 114 from the bottom side thereof against load and vibration at the time of mounting a component.
The board holding device 107 having the aforementioned structure is operated in the following manner. First, when a circuit board 114 is carried in the component mounting apparatus 101 by a loader, not illustrated, the endless flat belts 123 of the board holding device 107, which rotate in synchronization with the loader, carry the circuit board 114 and transfer the circuit board 114 to a mountable position. At a movement restricting position adjacent to the mountable position, a drawing-type stopper 116 protrudes in a manner so as to block the progressing path of the circuit board 114. When the transferred circuit board 114 comes into contact with the stopper 116, the circuit board 114 is positioned at the mountable position, and the flat belts 123 are also stopped simultaneously.
Next, the cylinder 119, which supports the support table 127 beneath the support table 127 so as to be freely raised and lowered, extends so that the support table 127 is raised, and the circuit board 114 is raised upward together with the holding rails 129 housing the flat belts 123. With this arrangement, the top face of the circuit board 114 is made in close-contact with the reference face forming the bottom faces of the reference rails 124, so that the circuit board 114 is positioned in the Z1 direction. Simultaneously, the plurality of support pins 128 attached to the pin supporting plate 130 come into contact with the bottom face of the circuit board 114 to support the circuit board 114 from the bottom side thereof, so that the circuit board 114 is supported so as to endure load and vibration applied at the time of mounting components 110.
With respect to the operation of the board supporting device 107 after mounting the components 110, in a manner reversed to the aforementioned operation, the cylinder 119 shrinks and the support table 127 is consequently lowered, so that the upward pressing force to the circuit board 114 by the flat belts 123 is released, and the supporting force applied to the circuit board 114 by the support pins 128 from the bottom side thereof is simultaneously released. Next, the flat belts 123 are again driven so that the circuit board 114 is further moved rearward in FIG. 12, and carried by an unloader, not illustrated, which is synchronously driven, and carried out of the component mounting apparatus 101. Simultaneously, the next circuit board 114 is carried by the flat belts 123 and transferred into the mountable position. Upon transferring the circuit board 114 out, the stopper 116 is once retracted downward to allow the circuit board 114 to move, and after the carrying-out process, the stopper 116 is again made face to face with the next circuit board 114 so as to protrude toward the movement restricting position.
The number of the support pins 128 to be attached to the pin supporting plate 130 is made different depending on various dimensions such as a plate thickness and an area of the circuit board 114 to be supported. In the case of a circuit board having a large plate thickness with a high degree of rigidity, the support pins 128 could be omitted in some cases; in contrast, in the case of a circuit board 114 having a small plate thickness with a wide width, a number of support pins 128 could be placed, for example, a 10 to 15 mm pitch might be used.
Moreover, in the case where, as illustrated in FIG. 12, a component 110, which has already been mounted on the bottom face of the circuit board 114, is present, the support pin 128 is not attached to a corresponding position of the pin supporting plate 130 (indicated by a vacant pin inserting hole 131) so as to avoid interference of the mounted component 110 with the support pin 128. Therefore, in response to the size of the circuit board 114 and the component mounting state onto the bottom face, each time the model changes in the circuit board 114 to be produced, a setup for changing the layout of the support pins 128 is required.
The support table 127 is secured to the component mounting apparatus 101 through the cylinder 119, and the surface of the support table 127 facing the circuit board 114 is adjusted so as to be in parallel with the bottom faces of the pair of reference rails 124 that position-restrict the circuit board 114 from above. The surface of the pin supporting plate 130 to be placed on the support table 127 is also secured so as to be in parallel with the bottom faces of the pair of reference rails 124 in the same manner so that this structure allows the respective support pins 128 attached to the pin supporting plate 130 to support the bottom face of the circuit board 114 from the bottom side thereof with even loads.
FIG. 13 illustrates each support pin 128. As illustrated in FIG. 13, the support pin 128 is constituted by a support portion 128a, a step portion 128b, and a securing portion 128c, which are generally formed into a cylinder shape. The tip of the support portion 128a is brought into contact with the bottom face of the circuit board 114 so as to support the circuit board 114, and the securing portion 128c, located on the opposite side, is inserted into each pin inserting hole 131 (see FIG. 12) that is formed in the pin supporting plate 130 so that the entire support pin 128 is supported in a direction substantially perpendicular to the surface of the pin supporting plate 130. In this case, the step portion 128b serves as a stopper while a bottom face portion 128d thereof is brought into contact with a region 132 around the pin inserting hole 131 on the surface of the pin supporting plate 130 so that a support height “h” from the surface of the pin supporting plate 130 (that is, the bottom face portion 128d of the step portion 128b) to the tip of the support portion 128a is defined. In this case, the support height “h” corresponds to a height at which the support table 127 has been raised to reach an upper dead center thereof. Here, in the example illustrated in FIG. 12, the support pin 128 is secured to the pin supporting plate 130 only by inserting the securing portion 128c so as to provide a sufficient attaching strength; however, the securing portion 128c may be threaded and engaged with a screw hole 131 on the pin supporting plate 130 side, if necessary.
The above explanation has been given in association with the component mounting apparatus 101; however, the same explanation is also given to a viscous material applying apparatus used for applying a viscous material such as cream solder. In other words, in place of the component, the aforementioned viscous material is supplied to the supplying section. In place of the suction nozzle 103, an applying nozzle is installed, and in place of the mounting head 104, an applying head is installed. However, except for the aforementioned points, the completely common structure and operation of the board holding device 107, in particular illustrated in FIG. 12, may be used between the two devices. Therefore, the following description will also be given by exemplifying the component mounting apparatus 101, unless otherwise required.
Here, in the conventional art, a support pin of the following type has been proposed in which, in order to easily attach the support pin 128 and strengthen the support by the pin supporting plate 130, notches are given to the step portion 128b and the securing portion 128c of the support pin 128 in the longitudinal direction so as to exert an elastic force (for example, Patent Document 1; see JP-A 05-191078). Moreover, another support pin of the following type has been proposed in which the entire support pin 128 is formed by an elastic body so that, when a preliminarily mounted component 110 is present on the circuit board 114, the support pin 128 is deformed by elastic property of the support pin 128 to avoid interference with the component 110. In this case, irrespective of the presence or absence of the mounted component 110, the support pins 128 may be left in their attached state (for example, Patent Document 2; see JP-A 2004-335973).
As described above, upon changing the model of the circuit board 114 during production, it is necessary to make a setup for changing the layout of the support pins 128 attached to the pin supporting plate 130 (in the case of the elastic body support pins also, it is necessary to change the layout depending on the width, length, and the like of the circuit board 114). One of the setups that have been made conventionally is a method in which support pins 128 are disassembled from the support table 127 together with the pin supporting plate 130 and transferred out of the component mounting apparatus 101 so that position-changing processes of the attached support pins 128 are carried out outside of the component mounting apparatus 101. One of the advantages of this method is that better operability is available in comparison with the method in which the position-changing of the support pins 128 is carried out inside the component mounting apparatus 101 that is limited in space, and it is possible to conduct efficient operations. Another advantage is that a so-called off-line setup is made in which a pin supporting plate 130, which has support pins 128 preliminarily laid out in accordance with the next model, is prepared, and the pin supporting plate 130 with the support pins 128 is attached to the support table 127 and while the manufacturing processes are carried out, the position-changing of the support pins 128 corresponding to the next model is conducted outside the component mounting apparatus 101.
In contrast, one of the disadvantages of this method is that the pin supporting plate 130 with a number of support pins 128 being attached thereto needs to be taken out of the component mounting apparatus 101, and thereafter, the pin supporting plate 130 with the support pins 128 needs to be again attached to the component mounting apparatus 101 upon mounting a component. In general, in order to make the pin supporting plate 130 lighter, the pin supporting plate 130 is made of aluminum; however, the resulting plate becomes as heavy as several tens of kilograms as a whole, and the operator has to enter a narrow space inside the component mounting apparatus 101 and take the pin supporting plate 130 out of the component mounting apparatus 101. Moreover, upon attaching the pin supporting plate 130, since the top face of the pin supporting plate 130 forms a reference face to the height of the support pins 128, the pin supporting plate 130 needs to be attached to the support table 127 while carrying out fine height adjustments so as to make the reference face parallel with the circuit board 114 (that is, the bottom face of the reference rail 124), with the result that an increased number of processes are required.
In the system of Patent Document 1 which forms the slit-shaped notch in the support pin 128 so as to provide the elastic property, although improvements can be achieved to a certain degree in comparison with the conventional solid structure, considerable labor is required for the attaching and detaching processes of the support pins 128. Moreover, in the system of Patent Document 2 which prepares the support pin 128 itself as an elastic body, depending on the amount of protrusion of the mounted component 110, the deformation of the component 110 and influences to adjacent components due to the elastic force of the support pin 128 tend to be caused, with the result that it is sometimes difficult to properly select a material having a suitable elastic force as the support pin 128. Furthermore, in both of Patent Documents 1 and 2, the structure in which, in order to support the circuit board 114, the step portion 128b is formed on the support pin 128 so that the support height “h” is determined by taking the surface of the pin supporting plate 130 as a reference is required in the same manner.